# abundance of grain

"much grain" or "plenty of grain" 

# crops

plants that people grow for food

# wave

Use the word for what long grass does when a gentle wind blows on it and it moves slowly back and forth.

# like Lebanon

"like the cedar trees in Lebanon."

# the people flourish in the cities like the grass of the field

The prosperity of the people in the cities is spoken of as if they were grass that grows abundantly in the fields.